Automatic electric switch, particularly for use in charging electric accumulators.



Nd 233L959 PATENTED SEPT. 25, 1906. 3' k H. LEITNEB, R. N. LUCAS & H. HILL.

AUTOMATIC ELECTRIC SWITCH, PARTICULARLY FOR USE IN CHARGING ELECTRIC ACCUMULATORS.

APPLICATION FILED FEB. 10, 1905.

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UNITED sTA'r s PATENT OFFICE;

HENRY LEITNER, OF WVOKING, RICHARD NORMAN LUCAS, OF BYFLEET,

AND HARRY HILL, OF WOKING, ENGLAND; SAID HILL ASSIGNOR T SAID LEITNER AND LUCAS.

AUTOMATIC ELECTRIC SWITCH, PARTICULARLY FOR USE IN CHARGING ELECTRIC ACCUMULATORS.

Specification of Letters Patent.

Patented Sept. 25, 1906.

Application filed February 10, 1906- Serial No, 2 %5128 To all whmn it may concern.-

Be it known that we, HENRY LEITNER, residing at Maybury, Wokin RICHARD N a MAN LUCAS, residing at Irynton, Dartnel Park, Bytieet, and HARRY HILL, residing at W oking, in the county of Surrey, England,

subjects of the King of Great Britain, have invented new and useful Improvements in Automatic Electric Switches, Particularly for Use in Charging Electric Accumulators, of

which the following is a specification.

Our invention'refers to certain improvements in automatic switches of the type employed for automatically connecting and dis- 1 5 connecting dynamo-electric generators from batteries of accumulators which they are arranged to charge. Our present invention is designed to get rid of the hunting to which most of these automatic switches are liable and provides means of short-circuiting the resistance of positive temperature coellicient which forms a feature of our systems until the dynamo excites and of breaking the shortcircuit after it has excited and when it as yet produces only a relatively small electromotive force and one insuiiicient to actuate an automatic switch of any of the types ordinarily in use.

In Patent No. 738,113 is shown one form or arrangement of devices illustrative of what has just been termed our systems."

We carry out our invention in practice by arranging in the circuit an electromagnet adapted to attract an armature when it is energized. This armature makes a contact when it is in its oil or unattracted position and a contact or contacts when attracted. The contact\vhich the said electromagnet makes in its said off position is arranged to shortcircuit the said positive-ternperature-coellicient resistance. The other two contacts are -arranged so that when one of them is made by the armature being attracted by the above-described electromagnet it puts the armature of the automatic cut-out across the terminals of the battery of zu'cumulators, while the second contact puts the line-wire field-winding of the cut-out in series with the dynamo, so that it tends to charge the battery of accumulators through it.

i In Order that the nature of our inventiol'r may be the more fully understood, we refer to the accompanying drawing, which illustrates it as applied to a system of electric lighting comprising a main generator con-- trolled by a subsidiary dynamo and a battery of accumulators charged by the main generator and an automatic switch.

In the drawings, a is the electromagnet, the windings of which are connected to the main generator d through the conductors Z and Z, so that it becomes energized when the main generator excites.

b is the armature of the said electromagnet, mounted on a plate of insulating material I), this plate making in the oii position the contact c" c. On the insulating-plate b is mounted a second metallic plate 0, which is adapted to make two contacts 0 and 0 when the electromaqne t a is energized and attracts its armature The contact 0 is connected to the conductor l by the flexible connection w, and the conducting-plate c is similarly connected to the conductor Z by the flexible connection w. I

(1 represents the armature of the main generator, and 9 its series ditl'erential field-wind ing, f being its fine-wire shunt field-winding;

is the armature oi the demagnetizing or controlling dynamo, designed to weaken the current through the winding f as the speed at .which the armature d is driven increases.

j is the tine-wire shunt field-winding of the controlling-dynamo. h is its series fieldwinding, and "i is the resistance of positive temperature coeilicient, which is, as will be seen, short-circuited 'by the contact c" 0 through the conductors Z Z, and Z".

Z: is the armature-winding of an automatic switch or cut-out for establishing (or breaking) connection between the. generator d and the battery B, according as the electromotive force of the former exceeds or falls short of that of the latter.

m is the lino-wire field-winding in the same, and n the coarse-wire fieldwvinding through which the charging-current passes from the main generator to the battery of accumulators B when they are being charged, ll ll being the incandescent lamps lighted by the latter.

1 and p are contact-pins carried upon th arm orlever of the automatic switch, designed to make contact in the mercury-trough 7 when the said switch operates and enable current to flow to the demagnetizer fieldwinding through the carbon resistances 0 l o and from the main generator to the battery B through the winding 11.

The operation of the arrangement is as follows: in the position shown in the drawing, which illustrates the state of all'airs when the main generator is at rest or until it has excited, the contact 0 short-circuits the resistance i, as already stated, by way of the conductors Z Z, and l, in this way facilitating the excitation of the main generator. \Vhen the main generator excites, the electromagnet (i receives current through Z", Z, l, and 1''. It thereupon attracts its armature I), breaking the contact 0, whereupon the plate 0' establishes contact between 0 and c and the conductor 1*, thereby putting a and c in direct connection with the positive terminal of the battery B. The armature is of the automatic switch or cut-out is thus placed across the terminals of the battery B, while the field-winding m of the automatic cut-out is put into series between the main generator and the positive terminal of the battery B. When the electromotive force of the generator continues to rise until it overpowers that of the battery B, the automatic switch is operated, owing to the increase of current passing through it, to cause the contacts 1) and p to descend into the mercury-trough r, situated below them, the contact 1) enabling the fieldwinding of the demagnetizing-dynamo to obtain current through the carbon resistances 0 0 and the contact p, enabling the main generator to charge the battery" B through the coarse-wire field-winding n of the automatic switch, the conductors Z and Z and the mercury-trough r.

It will be understood that the electromagnet (1 is so wound that it attracts its armature b and effects the various actions above described when the generator only produces a very small electromotive force. The armature 7c and the fine-wire field-winding m of the automatic switch therefore remain energized even when the charging-current flowingthrough 7! becomes very small, and in this way all possibility of the said automatic switch continuing to switch on and off when the dynamo is driven at some particular speed is averted.

Having now particularly described and ascertained the nature of our said invention and in what manner the same is to be performed, we declare that what we claim is 1. The combination with an automatic switch for switching a generator or dynamo into and out of connection with a battery of accumulators which it is designed to charge, and having a movable electromagnetic arma-w ture and a field-magnet with fine and coarse wire windings, of an electromagnet and means for energizing the same from the generator when it develops a low electroniotive force, and for then causing the electromagnet to make contacts which cause the armature of the automatic switch to be energized from the battery of accumulators and the finewire field-winding of the same to be put in series between the generator and the battery, substantially as described.

2. The combination with a generator, a batteryof accumulators, an automatic switch having fine and coarse field-windings for switching the battery into and out of connection with the generator, of an electromagnet in circuit with said generator, a movable armature for said magnet for closing a circuit from said battery through the armature of said switch and also closing a circuit from both the said battery and said generator through the fine field-winding of said switch, substantiallyas described.

HENRY LEITNER. RICHARD NORMAN LUCAS. HARRY HILL:

Witnesses: I

JOHN E. BOUSFIELD, C. G. REDFERN. 

